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` A 2Sheets-Sheet 1. E. P. TRAY'ER 8v' G. H. K UG'LER-,

(No MoaeL) TELEPHONE SYSTEM.

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TBLBPHONBSYSTBM- No. 377,788. Patented Peb. 14, 1888,.

By @Mfg/Wn UNITED STATES PATENT OFFICE..

EDWARD P. TRAYER AND GEORGE H. KUGLER, OF NEW YORK, N. Y.

ATELEPHONE SYSTEM.

SPECIFICATION forming part of Letters Patent No. 377.788, dated February 14, 1888.

Application tiled March 17, 1857. Serial No. 231,237. (No model.) i

' To all whom/ it may concern.-

Be it4 known that we, EDWARD P. 'PRAYER and GEORGE H. KUGLER, citizens ofthe United States, and residents of New York, county and State of New York, have invented certain new and useful Improvements in Telephone Systems, of which the following is a specilication.

The invention relates to improvements in i telephone systems whereby the number of any sub-station. 2ov

movements of the operator is diminished and the construction of. parts of the apparatus at the central station is simplified and made more efficient.

l right are shown the electrical connections bctween one sub station and the subscribers plug, annunciator, and test-Wire located at the central station. Figs. 2, 3, 4, 5, and 6 are different views (Fig. 4alone is shown in section) of three spring-jacks. Fig. 7 is a view, partly in section, ofthe subscribers plug. Figs. 8, 9,

and 10 are different views of the annunciator. Fig. 11 is a View, partly in section, of the apparatus or switch for throwing the test-wire in circuit.

As the invention relates to but a small part of a system well known, the description will be limited as far as possible to that small part.

rIhe test-wire and connections are substantially the same, except in so far as our invention is concerned, as in Patents Nos. 252,756, dated January 17, 1882, 308, 315, dated November 18, 1884, and 305,021, dated September 9, 1884.. Each springjack comprises four parts--the tube a, the test-Wire-spring terminal b pressing against said tube and connected to the test-wire c, a second spring, d, connected electrically both with the sub-station e through the line and with a terminal, f, opposite a spring-contact, g, which latter is connected electrically with the testspring b, and a contact-stripk, normally in contact with the spring d and in circuit with the annunciator-magnet i', asupport, j, the cordv plug, also in circuit With the weighted and pivoted lever m, having an insulated projection, n, the said lever being Aconnected electrically with the ground. n

From, the description so far given it is evident that when the subscribers plug is lifted from'the lever electrical connection is made 1 k, and the metal portions l of the subscribers between the spring g and the contactf, thus throwing the line into electrical contact with person, because the test-wire isa dead7 Wire connecting with duplicates or triplicates (not shown) of the tube a. and spring b. The'operator knows that some one else is using thesame line if she hears a click in the telephone appaf.

ratus. The way in which this click is'obtained is already well known in the art.

Our invention consists in providing an automatic test-,circuit connection in combination with the subscribers plug. By the mere lift-A ing of. this plug-that is, by one movement of the operator-it is at once known whether the line Wanted is or is not already in use.

The word Line7 in Fig, 1 indicates that that circuit 'is the main line, which therefore includes the subscribers instruments,`the ground e being at the subscribers station., In our invention the lifting of the subscribers plugV immediately places the main line in circuit with the test-wire, whereas in the patent No.y

356,859 the mere lifting of the subscribers plug does not place the test-wire in circuit with the main line. (See lines 81 to 87, inclusive, in said patent.)

A second part of our invention relates particularly to the apparatus.

Referringparticularly to Figs. 2, 3, 4, 5, and 6, the multiple spring-jack consists ofthe combination of an insulating-block, o, carrying tubes a, one spring, b, pressing againstthe tube, a second spring, d, and a third strip or spring, Vh, against which the second spring presses. ing-piece and carry a faceboard, p, by friction'.

It is evident that this 'face-board and the tubes may be separated from each other and from the block o for the purpose of polishing. the inner surfaces 0f the Atubes and of cleaningy The tubes a project from the insulatthe contact-surfaces between the outer surface of the tubes and the spring b.

Referring to Fig. 7, the plug consists of an insulating-tube, q, containinga metal piece, r, having a hole in one end and the plug s proper screwed into the other end, and a groove, t, containing a wire, u, which passes through said hole and into said groove.

Referring to Figs. 8, 9, and 10, the metal part c of the frame of the annunciator is one ter minal and the spring w is the other terminal, and is separated from the portion c by the insulating-support at'. When a current passes through the magnet i, the dropy falls, because the movement ofthe armature z raises the catch A. The falling ofthe drop,which is pivoted at its lower part at B, causes the end C to press the spring w upward against the metal parte, thus completing a local circuit,D, which may include an audible signal, such as an electric bell, b'. The solenoids i are held in their supports by screw-threads turned upon their cores.

We claim as our invention- 1. In a multiple-switchboard system, the combination of a switch having one of its terminals connected with .the main line and its other terminal connected with the test-Wire, and a subscribers plug normally carried by the operatinglever of said switch, the said main line normally including the subscribers instruments.

2. In a multiple-switch-board system, the combination of the usual spring-jack and an open switch normally carrying a subscribers plug, and in circuit with that terminal of said spring-jack which is connected to the main line and with the tube or mouth-piece of the springjack, said tube being electrically connected to the test-wire.

3. In a multi ple-switchboard system, the

combination of a main line including a subscribers instruments, a test or dead wire having electrical connections with duplicate springjacks, and an automatic circuitcontroller independent of said spring-jacks and normally maintained open byasubscribers plug, said controller being in circuit with the testwire and with the main line.

4. In a multiple-switchboard system, the combination of a subscribers plug` normally separating two electric contact-points, a main line, a test-wire, and an electrical connection between the testwire and one of the said contact-points, and another electrical connection between the main line and the other contactpoint.

5. In a multiple-sWitch-board system, the combination of a subscribers plug, an electric connection independent of a circuitinterrupter between the said plug and the main line, a spring-jack, an open switch normally carrying the subscribers plug and in circuit with the test-wire,with said spring-jack, and with the main line, and an operators plugin circuit with the operator-s instrument and normally in an open local circuit.

6. The combination of an insulating-block support, multiple springj acks mounted thereon having projecting and detachable receiving-tubes, and an insulating face-plate provided with holes which fit upon said projections.

In testimony that We claim the foregoing as our invention we have signed our names, in presence of two witnesses, this 15th day of March, 1887.

. EDWARD P. TRAYER.

GEORGE H. KUGLER. Witnesses:

EDWARD P. THOMPSON, JOHN l?. WRIGHT. 

